Hearing aids are often designed to change states (on and off) and modes (sleep mode, normal mode, phone mode, and other known modes) as necessary. Various methods of changing states and modes have been developed. The most common method includes manual switches for turning the hearing aid on/off. While manual switches are simple to use, such switches typically offer only binary state options, such as on/off. The manual switch requires the user to remember to turn off the hearing aid at night. Failure by the user to do so can result in battery charge losses of up 50% of the total battery life. Additionally, a mechanical switch potentially exposes the internal circuitry of the hearing aid to the elements, including contaminants such as water, and provides the hearing aid with a point of potential failure.
Another more elaborate method uses algorithms that monitor the sound conditions and change modes depending on the type/amount of noise in the user's environment. However, using a software solution to determine the state/operating mode of the hearing aid requires substantial programming and software development, generates additional strain and wear on the processor and microphone, and often requires a large portion of the circuitry to remain on during the off/sleep mode in order to wake the hearing aid later, unnecessarily depleting the battery.